PCR generated two distinct products from a toxic isolate of Alexandrium catenella, which had been taken from Dai Ya Bay (southern China), by using primers for large-subunit rRNA. This pattern is distinct from published data for North American Alexandrium species. Sequences of the two products suggest that the smaller was generated by a deletion event. Single-cell PCR generated the same pattern,...

The efficiency of PCR product cloning depends on the nature of the DNA polymerase employed because amplicons may have blunt-ends or 3' adenosines overhangs. Therefore, for amplicon cloning, available commercial vectors are either blunt-ended or have a single 3' overhanging thymidine. The aim of this work was to offer in a single vector the ability to clone both types of PCR products. For that p...

Real-time PCR monitors the amount of amplicon as the reaction occurs. Usually, the amount of product is directly related to the fluorescence of a reporter dye. Because it detects the amount of product as the reaction progresses, real-time PCR provides a wide linear dynamic range, demonstrates high sensitivity, and is very quantitative. The initial amount of template DNA is inversely proportiona...

We describe here a technique for allelic exchange in Francisella tularensis subsp. novicida utilizing polymerase chain reaction (PCR) products. Linear PCR fragments containing gene deletions with an erythromycin resistance cassette insertion were transformed into F. tularensis. The subsequent ErmR progeny were found to have undergone allelic exchange at the correct location in the genome; the m...

Many different strategies are used for cloning polymerase chain reaction (PCR) products. Some use restriction sites pre-integrated into primers or contained in a generated fragment. Others, such as the one used by Stratagene (La Jolla, CA, USA) in its pCR-Script Direct SK(+) Cloning Kit, are based on a blunt-end ligation. These strategies require the use of additional enzymes to polish the end...